There are 8 planets in our solar system. Until
2006 there were 9, but scientists decided that
Pluto wasn’t big enough to be a planet.
The eight plantets are:
At the centre of our solar system is the sun. The
sun is a star in our galaxy- The Milky way. It is
about 100 times bigger than the Earth. All
planets orbit around the sun in an eliptical
These four planets are also called terrestrial
planets, and are mostly composed of rock and
metal while outer planets are gas giants. They
are also smaller and have fewer moons.
The outer planets are much larger than inner
planets. Although mostly made out of gas, the
outer planets have other ingredients as well. At the
center that have a rocky core, although it is
sometimes composed of liquid metal.
The outer planets have a lot more moons than the
outer ones, for example, Jupiter has 63. Jupiter is
one of the brightest objects in the sky and has a
very stormy atmosphere. One major storm, the
Great Red Spot, is as big as the Earth.
Inner and Outer planets are separated by an asteroid
belt, which lies between Mars and Jupiter and it
contains asteroids made of rock and metal.
1. Everything orbits in the same direction
2. The Sun is just one star in 200 billion in the Milky
3. There are only a few stars within 10 light-years of the
Sun. The closest system is the Alpha Centauri
system, 4.4 light-years away
4. Astronomers used to think the Earth was the center
of the Solar system and the universe